1. Industrial Field of the Invention
The present invention relates to a pressurizing apparatus of a fuel tank and, more particularly, to a pressurizing apparatus of a fuel tank in such a machine as a working machine or vehicle on which a four-cycle engine or the like is mounted and in which the positional relation between the engine and the fuel tank changes.
2. Description of the Prior Art
In the case of a four-cycle engine, a fuel pump provided on an automobile or the like is generally known as an apparatus for pressurizing fuel. However, most of agricultural working machines such as mowers are of the type in which a fuel tank is located at a higher position than an engine so that fuel drops naturally and is supplied to the engine. For example, this type of apparatus are disclosed in U.S. Pat. Nos. 4,212,364 and 4,422,283. In such a case, the positional relation between a carburetor and the fuel tank in the direction of their heights is an important factor of the fuel supply capacity.
In this manner, when a four-cycle engine does not include the above-mentioned fuel pump, the positional relation between a carburetor and a fuel tank in the direction of their heights is an important factor of the fuel supply capacity. However, when the four-cycle engine is inclined during operation, this positional relation directly affects its performance on a slope.
For example, an automotive mowing machine of radio control type is the most effective when it is used for operation on a slope which has a large operational load and is highly dangerous. River banks are inclined at an angle of about 30 degrees in general, and some of the rough in golf links has an inclination as large as 50 degrees. However, fuel supply in a four-cycle engine employed at present can be conducted only when the inclination is 25 to 30 degrees at the maximum. Therefore, a fuel pump is indispensable for an engine of a machine which is operated on a steep slope, as described above. However, when the fuel pump is mounted, the machine becomes accordingly large in size and weight although a working machine, especially a working machine for steep-slope operation, is strongly demanded to be light and compact.
Taking such a problem into consideration, the present invention has an object to provide a fuel pressurizing apparatus which is light, compact, durable and inexpensive whereby a working machine can be operated even on a slope without any difficulty.